James Gurney

This daily weblog by Dinotopia creator James Gurney is for illustrators, plein-air painters, sketchers, comic artists, animators, art students, and writers. You'll find practical studio tips, insights into the making of the Dinotopia books, and first-hand reports from art schools and museums.

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Sunday, October 14, 2012

"I have noticed that when I paint outside I nearly always return with a less than bright painting. It will look good in the field but then look disappointingly desaturated in the studio. I assume this is because the pupils are so dilated outside and letting in so much light that when I'm back in the studio and my pupils are normal again and the light bouncing off the paint is considerably reduced (thus reducing chroma). I've thought I could make a kind of blinker out of black tubes to restrict the amount of light entering my eyes except in the foveal area. But due to my bifocals I doubt I could get such a gizmo to work. Obviously one could try and overcompensate for this effect by adding high chroma pigment but this seems untrue to the plein air idea. Have you run across any solutions to this problem?"

—Squinting

Dear Squinting,

I'm glad you raised the point because the same thing happens to me. I also notice a similar effect when I bring a finished painting from the studio outdoors into direct sunlight. The sunlight brings out all sorts of color and detail in the dark areas that I hadn't noticed in the studio.

In theory, when a person goes outdoors into bright light, the pupils should constrict to the appropriate size, just as a camera adjusts the exposure settings. This can take quite a few minutes, especially as we get older. When I first go outside, my eyes are dilated more than they should be, so it's naturally easier to distinguish those dark colors.

I asked a vision scientist how the sensitivity of the cones (color receptors in the retina) changes with increasing brightness levels, and I was told that the ability to distinguish colors increases with increasing light levels. In very low light, such as moonlight, the cones are barely functioning, but they get better and better at their job as the light increases—up to a point. In extreme glare conditions, such as bright white snow or sand, the color sensitivity begins to drop off. In that extreme environment, neutral gray sunglasses might help.

The best solution for me under normal conditions is to put a diffusing white umbrella over my work area so that the illumination on the work is close to the same as the illumination on the subject. Bright light in itself usually isn't the problem -- it's different amounts or kinds of illumination on the work and the subject.

I also try to avoid painting with the canvas or the palette in direct sunlight if I can help it, especially if the light on the painting is higher than the subject.

The issue may also be the kind of light you have indoors. As I'm sure you know, if you're working under incandescent or cool white fluorescent indoors, you're getting a distorted color rendition, so your eyes will have a hard time seeing color accurately whatever the light level. For suggestions on studio lighting, see the post linked below.

8 comments:

This brings up a question that I've often pondered. I've yet to try this experiment myself: What would happen if you painted plein air with sunglasses on? Would your color choices and mixes automatically correct so that the painting would come out "correct", since you're looking at the subject, the palette and the painting through the same lenses? (One reason I ponder this is that I've noticed that through my polarized sunglasses, there's a nice value separation - particularly in clouds- that isn't nearly as obvious without the glasses.)

I sometimes use a Best Brella, which is silver and black and really puts the painting in deep shade. Also I wear a brimmed hat. This opens my pupils so much that colors are brighter and more saturated than if I were in the sun. When I first noticed it, I thought the weather had changed!

Tom, I usually don't paint with sunglasses on, but I suppose if it's a neutral unpolarized gray filter, it should dim the colors equally. Polarized glasses selectively change the values, as you say, separating the values within the sky more and dimming the glare of wet street reflections. It's a matter of taste whether this helps your painting, but I avoid them because I'm usually trying to bring the values closer in the sky and I'm trying to push the bright values of reflections.

Linda, a lot of artists use the opaque silver and black umbrellas, but my own preference is for the white umbrellas, which give you a more reliable white light from above, instead of filling your visual field (and lighting your work) from the chance colors of ground reflections.

The opposite effect can happen when painting in reduced light; the values can become too high. The most effective strategy in all situations that I have found is to look for the lightest plane and establish it early. The important thing is to compare your paint mixture of the lightest plane to the white paint on your palette (get the mixture on your brush and hold it over the white paint); it should be a few steps below the white paint in value. You can then afterwards key all values below it.

One could establish value parameters to help control the averages. You could do this using a gray scale and find the values that relate to middle tones of a time of day. I've done this for painting observed views at night. For instance the middle of the palette for a sunny day will fall within a value 5 or 6 on the Munsell scale and if you make this choice the entire painting can be pitched based on this middle value. I have a paint mixing stick that I've painted with all 9 Munsell gray values that fits into my paintbox.It's a handy tool. Of course you could also be strategic, as Marc Dalessio describes in his wonderful blog. “For the last few years, the light effect that has most interested me is the high sun at midday. My subjects are also often north-facing, and thus back-lit. It’s usually an easy route to take for plein air painting. The number of hues is greatly reduced and the values and shapes become more important.”

A post on BoingBoing today about the giant fish eye that washed up last week goes into some detail on fish eye anatomy. Summary: because of the way their eye is built, it takes ten to twenty minutes for their eyes to adjust to bright or darker light:

I'm curious about this situation in which I have found myself. I am painting a subject in strong sunlight, but I have picked a stop that is in the shade for comforts sake. My pupils have to constrict to see the subject and then dilate to see the canvas over and over again. A couple of times I've had to stop painting because I have experienced a kind of "snow blindness". I imagine this situation also distorts the values and the colors as well. Is this something that's behind what's described?

I went to a contemporary art fair in Shanghai recently, which was a real eye-opener. Chinese contemporary arthas come leaps and bounds from the watery Zen landscapes to huge canvases of strange-looking beings. Theprices being asked and paid were huge too.Oriental, if not Chinese, my print of Jean-Léon Gérôme's painting, http://en.wahooart.com/A55A04/w.nsf/OPRA/BRUE-8BWS6R,bought some time ago from wahooart.com, is as lovely as ever.